This invention concerns a means for establishing the proper positioning of particularly the upper and lower posterior teeth during the setup stage of full denture fabrication.
The fabrication of full dentures normally involves several stages or steps. In a typical denture preparation, the dentist initially makes impressions of the upper and lower gums of the edentulous mouth using such as dental alginate impression material. Master casts of standard quality dental stone are then formed from the hardened and dried impressions. Acrylic resin record bases are molded from the casts after the ridge areas on the casts are built up with baseplate wax. During the so-called setup stage, occlusion rims of baseplate wax are formed on the record bases, the patient's bite registration is verified, and the anterior and posterior artificial teeth are set into the record bases with the aid of an articulator. The resulting trial dentures are then checked for fit, and permanent dentures are fabricated from molds of the trial dentures.
The crest of the lower ridge of the edentulous mouth is recognized as an important factor influencing the positioning of all lower posterior denture teeth. Lower denture stability generally occurs when the lower posterior teeth are positioned with their centers directly above or slightly lingual of the crest of the ridge. In current practice, this positioning is primarily attempted using the eye and judgement of the denture fabricator. Such a technique requires the ability of a skilled technician, and even then is highly subject to human error.
It is therefore the primary objective of the present invention to provide a means employing the lower ridge crest line which can be used by even relatively unskilled technicians to easily and accurately position the posterior teeth during the setup stage of full denture fabrication.